ANCHORAGE, Alaska (AP) -- While the brown bear viewing business in Alaska has been growing for more than a decade, in the last five years it has exploded, leaving land managers and biologists scrambling to figure out how to protect the bears and the sightseers.

Consider:

On Kodiak Island, after much debate, a new management plan was drafted this past year that puts bear viewers and bear hunters on equal footing when it comes to the island's wildlife trademark.

In Katmai National Park, the number of commercial operators, which includes air taxis that take tourists bear viewing, has nearly tripled -- from 53 to 152 -- in the past 10 years.

And in Southcentral, and particularly out of Soldotna and Kenai, dozens of small air taxis that once focused on the sale of fishing trips are now giving equal, and in some cases greater, billing to bear viewing trips. They report record numbers of clients.

For example, on remote Wolverine Creek, due west of Nikiski across Cook Inlet, the number of bear watchers jumped from about 2,200 in 1999 to 6,000 in 2000, according to rough figures compiled by the Alaska Department of Fish and Game. The state agency responsible for management here, Fish and Game expects that number could reach 8,000 when the 2001 season figures are tallied.

Everyone in the air taxi business ''is jumping on it because it is a good revenue source,'' said Stan Divine, an office manager for Andrew Airways in Kodiak.

''There certainly has been a huge explosion that we are all aware of,'' said Chris Day, an owner of Emerald Air in Homer. ''We didn't understand what the possibilities were until five years ago.''

While the increased interest is a moneymaker, some problems have begun to appear.

Bears have reportedly climbed into viewing skiffs. In one incident, the weight of the bear caused the boat to start taking on water. The bear had its front paws on the gunwales and was reaching for fish on the bottom of the skiff, according to state reports. As the bear tried to climb aboard, the clients moved to the other end of the boat and the guide started whacking the bear over the head with a paddle. The bear retreated.

That's not the only report of a bear being hit over the head with a paddle, according to Joe Meehan, a state Fish and Game wildlife habitat biologist. Bears also have been reported trying to grab salmon off of stringers.

No one has reported any viewers injured, but officials do have reports of three bears shot in defense of life and property since the early 1990s, including one bear found dead floating in a lake, Meehan said.

One of the biggest problems wildlife biologists and public lands managers face outside of park boundaries in Alaska is that state and federal laws limit their ability to dictate how tour companies can operate. Today, they can only cite operators for directly harassing wildlife.

Almost everyone involved with wildlife viewing, however, expects that is about to change.

BEARS DRAW BIG BUCKS

Why the sudden spike in bear viewing?

Guides, resource managers and biologists point to the convergence of four events.

One, television shows and documentaries focusing on brown bears -- including a National Geographic film that featured the brown bears of Kodiak Island -- have proliferated. Many show people walking within feet of big, photogenic bears without incident.

Two, at the same time, tourism in the state has jumped from an estimated 880,000 visitors in 1990 to more than 1.4 million in 1999.

Three, ''people are learning that they (coastal brown bears) can be safely observed,'' said Derek Stonorov, a Homer biologist and guide. The animals, at least in certain situations, can habituate to people rather quickly.

And four, prime bear viewing sites operating on state or federal land, such as the McNeil River State Game Sanctuary or Admiralty Island's Pack Creek in Southeast, closely regulate the number of visitors in order to preserve the wild experience and to protect the bears. They are turning away visitors willing to pay to see bears in the wild.

Most Cook Inlet tour operators now charge between $275 and $500 for a bear viewing trip. The total gross receipts for the operators on the Katmai coast alone totaled $2.5 million in 1999, according to numbers collected from the National Park Service.

Tour operators have found bears generally easy to work around. Despite their reputation for ferocity, bears do not stake out and defend territories, but instead roam ranges.

Coastal brown bears, unlike Interior brown bears, have small ranges because of the comparatively abundant resources of the coast. In order to take advantage of some of those resources, particularly returning salmon, coastal bears have also been conditioned to tolerate other bears in close quarters. In some situations, this habituation can be extended to tolerance for humans.

Interior brown bears have been known to charge people from up to one-eighth mile away, according to bear biologist Tom Smith of the U.S. Geological Survey who has studied bear and human interactions in Katmai.

''Personal space that is measured in the quarter-miles shrinks to the length of paw on the coast,'' Smith said. ''So now you have all these socially adapted bears that don't have a sudden hair-trigger.''

Bear viewing has proven generally safe, Smith said. Statistically, he noted, the people most likely to be injured or killed by bears are hunters, who surprise the animals while moving quietly through the woods or run into them when packing moose or caribou or other meat.

Katmai reported 71,000 visitors last summer, up from 43,000 in 1997, without a serious incident. Visitors at Katmai's Brooks Camp are allowed to basically wander freely among salmon-feeding bears. The last injury was reported in 1991 when a seasonal ranger ran from a charging bear and was bit on the hand. Neither McNeil River, which has been operating for more than 30 years, nor Pack Creek, which has been regulated for years, have reported injuries.

No injuries have been reported at a half-dozen new bear viewing sites that are largely unregulated, but biologists fear it's just a matter of time.

''We don't know what carrying capacities are and that is key,'' said John Schoen, a biologist with the Alaska office of the National Audubon Society, who has been alarmed by some of the bear viewing practices he has seen at the new sites. ''We really need good research, and we need to establish guidelines and protocols before patterns get established.''

ETHICAL CONCERNS

The main problems of the moment, according to biologists and land managers, are twofold.

One, ''commercial filmers are going out there and showing things we don't allow, like getting too close to the bears, which gives the wrong message,'' said Becky Brock, head of concessions for Katmai National Park. And two, many of the new areas operators have found are on land owned by the state or privately or by a Native corporation, which makes standardizing and enforcing rules difficult.

Right now, policy is to control bear viewing activity on state land with educational efforts, although state officials are also working closely with park officials to devise consistent rules and guidelines.

Meehan said he expects that some sort of regulations will be needed within the next couple of years.

About 100 miles to the north of the Katmai Park boundary, Chinitna Bay sits on the fringe of Lake Clark National Park and Preserve. The 10-mile-long bay has a number of private inholdings, including land owned by Mary and Bob Haeg.

The Haegs have called the bay home for 25 years and in recent years have watched the bear-viewing business destroy their private Xanadu.

''We're to blame,'' said Mary Haeg. ''Right after the oil spill, when our fishing business went down, we started a tourism business, Haeg's Wilderness Lodge. We kept it small.''

Small as it might have been, however, it attracted notice.

Before long, tour operators from neighboring lodges recognized a rich opportunity for bear viewing and started bringing tourists to the bay in air boats, Haeg said.

Lake Clark park records show that only about 30 visitors came to the north shores of the bay in 1995; by 2000 that had jumped to 208. Because the bay is a hodgepodge of state, federal and private land, there is no one set of rules regulating use of the area.

''It's frightening,'' Mary Haeg said. ''We have a very shallow bay, and the air boats are disturbing (salmon spawning beds). ... We don't see belugas anymore. Our blue mussels are gone.''